Mechanical acceleration integrator



Sept. 19, 1950 J. RABlNow IECHANICAL ACCELERATION INTEGRATOR 2 Sheets-Shut 1 Filed lay 5, 1946 I Fla.

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ATTORPEY Sept. 19, 1950 J. RABlNow MECHANICAL AccELmnon :manon 2 Sheets-Sheet 2 Filed lay 3, 1946 wvl n m cfu 0 w a 9 a.\\ s 4.0 \\l 5 0 \a n 5 u :lv 4 o O a 4,2 n a uw .H u

INVENTOR JACOB RAB/NOW ATTORNEY tentait Sent. i9, '1950 MECHANICAL ACCELERATION IN TEGRATOR Jacob Rabinow, Washington, D. C., assignor to the United States of America as represented by the Secretary of the Navy Application May 3, 1946, Serial No. 666,926 8 Claims. (Cl. 20G-52) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) This invention relates to acceleration integrators for establishing a time interval which is a function of the acceleration of the whole integrator. More particularly, the invention relates to a novel integrator of the character described in which the linear acceleration of a rotary mass which is a part of a moving machine and is affected by changes in velocity of movement of that machine, is converted to rotary acceleration of a centrifugal switch. The device is useful as part of a bomb releasing mechanism in an airplane adapted to toss bombing, although its use is not limited thereto.

One object of the present invention resides in the provision of an acceleration integrator having means for converting the linear acceleration of a rotary weight into rotary acceleration of a centrifugal switch, to establish a time interval which is a function of the linear acceleration of the entire integrator.

Another object of the invention is to provide an acceleration integrator of the character described, having means for adjusting the acceleration response of the centrifugal switch.

Another object is to provide an acceleration integrator of the character described. having mechanism for resetting the integrator for a new operation, the resetting mechanism being independent of the operating components of the integrator.

These and other objects of the invention may be better understood by reference to the accompanying drawings, in which Fig. 1 is a front view, partly in section, o one form of the new integrator;

Fig. 2 is a plan view of the integrator shown in Fig. 1;

Fig. 3 is a side view of the integrator shown in Figs. 1 and 2, with parts broken away, and

Fig. 4 is a diagrammatic perspective view of part of the integrator.

Referring now to the drawings, I have shown a mounting plate I for supporting the operating parts of the integrator. Secured to the plate I, as by means of screws 2, are lateral posts l, '4 and 5, to the outer ends of which a T shaped bearing plate 8 is secured by screws l. A sector-shaped gear 8 is pivoted in bearings l and III mounted in the T plate 6 and mounting plate i, respectively, and is formed with an ear II below and to the right of its pivotal axis, as shown in Fig. l. When the gear 8 is in its upper position (Fig. 4), the ear II is in contact with the lower end of a hollow rod assembly I2 having a spring-pressed detent I2a slidable 2 in the lower end of the rod and engaging the ear II. The rod assembly I2 is urged downwardly by a spring I3 acting through a transverse pin I4 movable vertically in lateral slots I2b in the rod I2 and its detent I2a, against the upward pressure of a smaller spring I5 within the detent I2a. Hollow rod I2 is secured around a solid iron rod I8 which extends into and forms the movable core of a solenoid II suitably secured to the plate I. The upper end Ita of the rod I6 is frustro-conical in shape and, with the similarly-shaped lower end of the upper fixed core I'Ia of the solenoid II, forms a symmetrical air gap I8. An elongated pin I9 extends loosely through the fixed core IIa and through a plate 20 fixed to the upper end of the solenoid Il, the lower end of the pin being threaded into the upper end of the rod I6. The pin I9 is supported on the plate 20 by lock nuts Ila adjustable to vary the position of the pin I9 and therefore the position of the rods I6 and I2 with respect to the ear II. It will be understood that the rod detent I 2a normally is in spring-pressed contact with the ear II, as shown in Figure 1. When the solenoid I1 is energized, the movable core I6 of the solenoid will be drawn upward against the tension of spring I3, moving the attached pin I9 and rod I2 also upward.

It will be observed from Fig. 2 that the left side 8a of the gear sector 8 is of increased thickness to add to the rotative movement of the sector about its pivotal support when the plane of Figure 1 is upright. A spring 2I surrounds the sector shaft and has one end secured to the T plate 6 and the other end fixed to the sector 8. The spring acts in a direction to move the sector upwardl so that the force" acting on the sector is proportional to the acceleration minus a factor determined by spring 2l.

As shown in Figure 1, the gear teeth of sector 8 mesh with a pinion gear 22 to rotate a large bevel gear 23 fixed to pinion* 22 and mounted in bearings in the plates I and 6. A vertical shaft 24 is rotatable in the lateral post 4 by means of pinion 25 meshing with gear 23, and has at its upper end a disk 26 secured to a collar 24a pinned to the shaft 24. A centrifugal switch 2'I operated by the rotation of the disk 26 comprises a bell crank member 28 having a long arm 28a carrying at its' outer end an electrical contact 29, and a short arm 28h pivoted at 30 in spaced blocks 3| mounted on the disk 26. An adjustable stationary contact screw 22 is threaded through a block of insulating material 3 I3 secured to the mounting plate I by screws I4.

Special attention is directed to the variable biasing means for the centrifugal switch. It comprises a divided spring having two legs 35 and 36 attached at their remote ends to spaced screw posts 31, 38 threaded into the disk 25 and through a balance weight 38 thereon. The spring legs 35 and 35 are attached at their adjacent ends to a screw 40 having a tapered lower end supported by a thrust bearing in the arm 28a, and having its upper end disposed for rotary adjustment in 90 increments in an upper plate 44 suitably fixed to the arm 28b. Rotation of screw 40 will raise and lower the common ends or the springs 35 and 35 and thus vary not only the tension exerted by the springs as the latter are stretched but also the lever arm of the springs with reference to the fulcrum-pivot 38. Thus, the biasing means Il, 25 for the bell-crank centrifugal switch may be given a precise adjustment through the quarter revolution positions oi the screw 40 without disturbing the position of the center of gravity of the bell-crank 28.

A brake and latch mechanism for the integrator comprises a bell crank rod 45 loosely journaled in spaced blocks 45, 41 on the plate I and having a horizontal arm 48 xed to one end of the rod 45 for upward movement by the upper end of the pin I9. The rod 45 also has a vertical arm 49 at its other end, mounted to move forwardly upon upward movement of arm 48 and thus move an arm 50 outwardly. The arm 5U is fixed to a rod I loosely journaled in block 41 at one end and at the other end in a recess in the post 4. Angular movement of rod 5I due to outward movement of arm 50 lowers one end 52 of a bell crank 53 fixed at its vertex to rod 5|, thereby moving backwardly the forwardly projecting lower end 54 of the bell crank. The end member 52 has its upper surface covered with frictional material 52a for exerting brake action on the lower side of the disk 25 upon angular movement of rod 5I due to spring 55. The latter, as shown in Figure 3, is connected at its lower end to a stud 55a on plate I and at its upper end to a lateral projection 55b on rod 5I. The lower end 54 of the bell crank is disposed beneath the lower edge of the gear sector 8 and through the action of spring 55 retains the sector in its upper position until the solenoid I1 is energized.

The operation of the integrator will be apparent from the foregoing description. Upon energization of the solenoid I1, the rod I2 will be lifted from the ear II, and the upper pin I9 will push upwardly on the arm 48, releasing the brake 52a on bell crank 53 and retracting the stop 54 to allow the gear sector 8 to move downwardly and rotate the centrifugal switch 21. It will be seen that closure of the switch contacts 29--32 is dependent on the acceleration with which the integrator is carried through space, this acceleration adding'directly tolthe acceleration given to the gear sector by gravity. The time interval is, of course, measured from the instant the'solenoid IBa is energized.

The centrifugal force required to close the switch contacts 29-32 may be varied by adjustment of screw 40. This force is obtained through rotation of disk 2B by downward movement of sector 8, against spring 2|, under the influence of gravity and linear acceleration of the device, when the sector is released upon energizing of solenoid I1. It will be understood that the acceleration of the device is upward as seen in Fig. 1. Thus. the closing of switch contacts 29- 22 means that the device has attained a certain acceleration predetermined by the setting of screw 4l, and by measuring the time interval between release of sector 8 and closing of contacts 28-22, the average rate of acceleration can be determined.

This acceleration integrator is useful in toss bombing where it is desirable that the bombs follow the correct trajectory. During the bombing run, the pilot puts his sight on the target and actuates solenoid I1 at the time that he pulls the aircraft upwardly off its course. The gear sector 8 is now free to move under the acceleration forces and to integrate the acceleration forces with respect to time to obtain a factor proportional to vertical velocity. When the desired upward velocity of the plane is obtained. the centrifugal switch will close and release the bombs.

It will be apparent that the acceleration integrator may be readily reset by deenergizing the solenoid I1, whereupon spring I3 returns the rod assembly I2 to its lowermost position against ear I I, thus raising gear sector 8 about its axis 9-I0 to its original position, with the aid of spring 2I. concurrently with deenergizing of the solenoid I1, the arm 48 is released by pin I9 so that shaft 5I is rocked back to its initial position by spring 55, this initial position being determined, as shown, by an adjustable stop engaging a lateral arm 5I on shaft 5I. The bell crank 53 is thus moved to replace its lower end 54 in its normal retaining position under gear sector 8, and to move its other end 52 in position for engaging the brake 52a with disk 2G. It will be understood that the bell crank 53 may be held manually to prevent engagement of brake 52a with disk 25, to permit rotation of disk 2E incident to return of sector gear 8 to its initial position.

'I'he invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. In an acceleration integrator, a gear sector mounted for rotation about an axis, a rotatable switch assembly operable by centrifugal force incident to rotation of the assembly, a gear train between said sector and switch assembly for rotating the assembly upon movement of the sector about its axis in response to acceleration of the integrator, means for locking the sector against movement, brake means for securing the switch assembly against rotation, and means for releasing said brake and locking means.

2. In an acceleration integrator, a gear sector rotatable about a..A axis in response to acceleration of the integratorand at a rate proportional to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a. gear train between the sector and the switch assembly for rotating said assembly to operate the switch under centrifugal force, means for locking the gear sector against rotation, and means for releasing said locking means.

3. In an acceleration integrator, a gear sector rotatable about an axis in response to acceleration of the integrator and at a rate proportional to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a gear train between the sector and the switch assembly for rotating said assembly to operate the switch under centrifugal force, means for locktion of the integrator and at a rate proportional i to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a gearl gear sector against rotation, brake means for? securing the switch assembly against rotation, and an electromagnetic device for releasing said locking means and said braking means;

5. In an acceleration integrator, a gear sector rotatable about an axis in response to acceleration of the integrator and at a rate proportional to the magnitude of the acceleration, a switch assembly operable by centrifugal force, means for adjusting the switch assembly to vary its response to centrifugal force, a gear train between the sector and the switch assembly for rotating said assembly to operate the switch under centrifugal force, means for locking the gear sector against rotation, and means for releasing said locking means.

6. In an acceleration integrator, a gear sector rotatable about an axis in response to acceleration of the integrator and at a rate proportional to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a gear train between the sector and the switchA assembly for rotating said assembly to operate the switch under centrifugal force, a rod assembly, a spring normally urging the rod assembly against part of the gear sector to lock the sector against rotation, a bell crank having one arm normally locking the gear-sector against rotation and having the other arm normally engaging the switch assembly to brake the assembly, and an electromagnet for actuating the rod assembly against said spring to disengage the sector and for moving the bell crank to release the gear sector and the switch assembly.

7. In an acceleration integrator, a gear sector rotatable about an axis in response to accelera-y tion of the integrator and at a rate proportional 6 y to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a. gear train between the sector and the switch assembly for rotating said assembly to operate the switch under centrifugal force, af rod assembly, a spring normally urging the rod assembly against part of the gear sector to lock the sector against rotation, an electromagnet for actuating the rod assembly to disengage the same from sector, a bell crank having one arm normally locking the gear sector. against movement and having the other arm normally engaging the 'switch assembly to brake the assembly against rotation by the gear sector, and means operable by the rod assembly for moving the bell crank to release the gear sector and the switch assembly.

8. In an acceleration integrator, a gear sector rotatable about an axis in response to acceleration of the integrator and at a rate proportional to the magnitude of the acceleration, a switch assembly operable by centrifugal force, a gear train between the sector and the switch assembly for rotating said assembly to operate the switch under centrifugal force, a rod assembly, a spring normally urging the rod assembly against part of the gear sector to lock the sector against rotation, an electromagnet for actuating the rod assembly to disengage the same from the sector. a bell crank having one arm normally locking the gear sector against movement and having the other arm normally engaging the switch assembly to brake the assembly against rotation by the gear sector, means operable by the rod assembly for 'moving the bell crank to release the gear sector and the switch assembly, and means for returning the bell crank to its normal position upon deenergizing of the electromagnet.

, JACOB RABINOW.

REFERENCES CITED The following references are ofrecord in the le of this patent:

UNITED STATES PA'I'ENTS is Number Name Date 971.334 Whalen Sept. 27, 1910 1,684,132 Hewlett Sept. 11, 1928 2,199,672 Peterson May 7, 1940 

